Vacuum cleaner with improved fan arrangement



3 Sheets-Sheet 1 M. D. TUPPER VACUUM CLEANER WITH IMPROVED FAN ARRANGEMENT Filed Sept. 19, 1956 5in 1 um -/mum May 9, 1961 May 9,1961 M. D. TUPPER 2,982,986

VACUUMCLEANER WITH IMPRovED FAN ARRANGEMENT Filed sept. 19, 195e 3 Sheets-Sheet 2 F772' am @nml /12 l/evz tor' /7919 Attorney.

May 9, 1961 M. D. TUPPER VACUUM CLEANER WITH IMPROVED FAN ARRANGEMENT Filed sept. 19, 195e 3 Sheets-Sheet 3 F/glf.

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United States Patent O VACUUM CLEANER WITH IMPROVED FAN ARRANGEMENT Myron D. Tupper, Fort Wayne, Ind., assignor to General Electric Company, a corporation of New York Filed Sept. 19, 1956, Ser. No. 610,768

8 Claims. (Cl. 15-327) This invention relates to uid moving apparatus and more particularly to a vacuum cleaner having an improved fan arrangement.

Vacuum cleaners are used under varying conditions where different responses of the cleaner are necessary to effect the desired purpose. Thus, when a vacuum cleaner is being used to clean a smooth surface, it is desirable that a high flow of air be provided but it is not necessary that a high vacuum be achieved. In fact, it often is not desirable to provide a high vacuum in cases where the flow is high because of the load placed on the vacuum cleaner motor. On the other hand, where the vacuum is used to clean fabric surfaces such as tapestries, sofas, and the like, it is important that a high suction be provided to draw air through the cloth so as to take up threads and other items attached to the fabric. Thus, where the flow is low because of the obstruction of the fabric against the nozzle of the vacuum cleaner, it is important that the suction provided be high. While todays vacuum cleaners provide a head-to-flow relationship wherein the head decreases as the ow increases, only a relatively gradual change in head as the flow increases has in the past been achieved. The optimum situation is to have a very high head at low flow, decreasing rapidly. to a relatively constant low head as the flow increases beyond a very small amount. The characteristics of the head and amount of ilow are, of course, primarily determined bythe type of fan driven by the motor of the vacuum cleaner.

It is, consequently, an object of this invention .to provide an improved vacuum cleaner incorporating a fan arrangement which will provide low and high heads at high and low rates of ow respectively.

In one aspect thereof, this invention provides a vacuum cleaner having a casing with a motor positioned in the casing. A high-head low-flow fan and a low-head highflow fan are both mounted so as to be driven by the motor, and the two fans are arranged in series relation, i.e., the outlet of one of the fans is connected with the inlet of the other of the fans. At a low rate of flow, the effect of the high-head fan will be predominant to create a high degree of suction. As the rate of flow. increases, the effectiveness of the high-head fan decreases very rapidly while the effectiveness of the low-head highiiow fan increases. Therefore, an increase in flow will cause a rapid decrease in the suction.

The features of the invention which are believed to be novel are set forth with particularity in the appended cla-ims. The invention, itself, however, both as to its organization and method of operation, together with further objects and advantages thereof may best be understood by reference to the following description taken in connection with the accompanying drawings.

In the drawings:

Figure l is a side View, partly broken away andpartly in cross section, of the electric motor used for actuation purposes and the preferred embodiment of the improved fan arrangement to be incorporated in the vacuum cleaner;

Patented May 9, 1961 partly broken away, of an electric motor and a second embodiment of the improved fan arrangement of this invention; and

Figure 8 is a view along line 8-8 in Figure 7.

Referring now to Figures 1, 2 and 3 of the drawings, there is shown a vacuum cleaner, generally indicated at 1, having a casing 2 with an inlet opening'S adapted to receive the end portion 4 of a hose 5 which is provided at its other end with a suitable cleaning tool 40. A bag 6, formed of porous material which allows the air to pass through it but retains the dust and dirt, is positioned in casing 2 as shown, with its opening connected to opening 3 in the usual manner (not shown). Also positioned within vacuum cleaner casing 2 is an electric motor, generally indicated at 7, having a casing 8 with openings 9 provided therein. Motor 8 is usually, although not necessarily, of the alternating current series wound type with an armature 10, a commutator L11, and brushes 112 to provide the connection across a source of power for 'the commutator and the armature. A sealing member 13 extends between motor housing 8 and the vacuum cleaner casing 2, as shown. This sealing member precludes passage of air outsidel the motor housing 8 in casing 2, and forces the air to pass through openings 9 'and then downwardly through the motor.

' A stationary shroud member 20 includes an inner portion 21 in close. running clearance with portion 16; port-ion |21 is curved so as toy cooperate with portion 16 of part 15 to provide a vortex fan assembly with an inlet 22 and an outlet 23 separated by solid baffle-like portion 24. Portion 41 of part 20 is in close running clearance with blades 19 and cooperates with portion 17 of part 15 and blades 19 to form a radial fan assembly with its inlet coinciding with outlet 23 of Vthe vortex fan assembly.

The ordinarily designed radial fan assembly, as is well known, furnishes a relatively high-flow low-head arrangement. This is illustrated by Figure 4 which is the head-How curve for a 7 inch radial fan rotating at 16,000 r.p.m. The vortex fan assembly, on the other hand, is known to furnish a relatively high head for its size, and a relatively low flow, with the head decreasing to the vanishing point as the ow increases. This is illustrated in Figure 5, the head-How curve for a 3 inch vortex fan rotating at 16,000 r.p.m. Referring particularly to Figure 2, it will be seen that the two fan assemblies are in series flow relation with each other, outlet 23 connecting directly with the radial fan assembly. In such a case, the heads of the two fans are added for any given flow. Figure 6 shows a composite curve of this type, derived from the curves of Figures 4 and 5. Thus, when an obstruction is placed in front of the vacuum cleaner tool 40, as where the tool is placed against tapestries or sofas or the like and the fabric substantially blocks the tool opening, the ow (as indicated by the arrows of Figures 1 and2) is low enough so that the vortex fan blades 18 create a high suction, as is desired in such a stantial obstruction to the vacuum cleaner opening, theA head created by radial fan blades 19 is then sufficient for good cleaning action, and the design of th e radial fan causes it to move a substantial amount of air through the machine to enable good and rapid cleaning action.

It will be seen that the provision in vacuum cleaner 1 of the two different types of fans, one of a high-head low-flow nature and the other of a low-head high-flow type, will cause the desired amount of suction to be exerted by the vacuum cleaner in automatic response to the particular cleaning situation.

Referring now to Figures 7 and 8 of the drawings, there is shown a second embodiment of the invention with like parts being designated by the same numerals as applied to Figures l to 3. A fan member 25, concentrically mounted on the end of shaft 14, includes an inner back plate portion 26 with a plurality of radialtype-fan blades 27 secured thereto, and an outer portion 28 dening an annular recess of semicircular cross section within which a plurality of vortex-type-fan blades 29 are provided. A shroud member 30 is secured to motor housing 8 so as to be rigid therewith. Shroud 30 includes a pair of portions 31 and 32 which cooperate with portion 26 of fan member 25 to provide a scrolltype housing for the radial fan blades Z7 with an outlet opening 33. Portion 31 of shroud 30 is formed to provide a radial inwardly positioned inlet opening 42 from motor 7 to complete the radial fan assembly.

Portion 34 of shroud 30 is in close running clearance at 35 and 36 with portion 2S of fan member 25 so as to form a vortex fan assembly having an inlet 37 and an outlet 38 separated by a solid baffle-like part 39 formed in portion 34 of member S.

It will be seen that the arrangement of Figures 7 and 8 provides a pair of fans in series relationship, as before, with one of the fans being of the high-head low-flow type (the vortex fan) and the other being of the lowhead high-ow type (the radial fan). By reversing the radial position of the fans, the construction of Figures 7 and 8 locates the vortex fan radially outwardly of the radial fan.

While the invention has been explained by describing particular embodiments thereof, it will be apparent that improvements and modifications may be made without departing from the scope of the invention as defined in the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. For use in a vacuum cleaner having an electric motor including a shaft extending therefrom, a high-head low-tlow vortex type fan concentrically mounted on said shaft, and a low-head high-How fan concentrically mounted on said shaft, one of said fans being disposed within the other, said fans having means for connecting the outlet of one of said fans with the inlet of the other of said fans for directing substantially all of the tlow from said one fan to said other fan whereby said lowhead high-dow fan moves a substantial amount of air when the inlet to said fans is substantially unobstructed and said high-head low-flow fan provides a substantial head when the air liow decreases because of an obstruction in the inlet to said fans.

2. For use in a vacuum cleaner having an electric motor including a shaft extending therefrom, a fan member concentrieally secured to said shaft and having two face portions, said member having two pluralities of fan blades formed on the same face thereof, and means arranged in cooperative relationship with said pluralities of fan blades to form respectively a highhead low-How vortex type fan and a low-head high-flow fan in series flow relation, said means connecting the outlet of one of said fans with the inlet of the other of said fans for directing substantially. all of the flow from said one fan to said other fan, whereby said lowhead high-flow fan moves a substantial amount of air when the inlet to said fans is substantially unobstructed and said high-head low-flow fan provides a substantial head when the air tiow decreases because of an obstruction in the inlet to said fans.

3. For use in a vacuum cleaner having an electric motor including a shaft extending therefrom, a fan member concentrically secured to said shaft, inner and outer concentric pluralities of fan blades formed thereon, and means arranged in cooperative relationship with said pluralities of fan blades respectively to form a highhead low-ow vortex type fan with said inner plurality and a low-head high-flow fan with said outer plurality in series ow relation, said means connecting the outlet of said high-head low-flow fan with the inlet of said lowhead high-flow fan for directing substantially all the ow from said high-head low-flow fan to said low-head high-dow fan whereby said low-head high-flow fan moves a substantial amount of air when the inlet to said fans is substantially unobstructed and said high-head low-flow fan provides a substantial head when the air tlow decreases because of an obstruction in the inlet to said fans.

4. For use in a vacuum cleaner having an electric motor including a shaft extending therefrom, a fan member concentrically secured to said shaft, inner and outer concentric pluralities of` fan blades formed thereon, and means arranged in cooperative relationship with said pluralities of fan blades respectively to form a low-head high-flow fan with said inner plurality and a high-head low-flow vortex type fan with said outer plurality in -series flow relation, said means connecting the outlet of said low-head high-flow fan with the inlet of said high-head low-ow fan for directing substantially all of the flow from said low-head high-dow fan to said high-head low-flow fan whereby said low-head high-flow fan moves a substantial amount of air when the inlet to said fans is substantially unobstructed and said highhead low-flow fan provides a substantial head when the air flow decreases because of an obstruction in the inlet to said fans.

5. A vacuum cleaner comprising a casing forming a passage for air, said passage having an inlet and an outlet, a dust collecting means connected to said inlet and forming an air entry path thereto, means in said passage between said inlet and said outlet for removing foreign matter from the air passing therethrough, a motor disposed within said casing, and fan means driven by said motor and positioned in said passage for moving air therethrough, said fan means comprising a high-head low-flow fan, and a low-head high-flow fan, said fans being arranged in series flow relation with said passage and with each other, the outlet of one of said fans being connected with the inlet of the other of said fans whereby said low head high-flow fan moves a substantial amount of air when the air entry path to said passage is substantially unobstructed and said high-head low-flow fan provides a substantial head when the air flow decreases because of an obstruction in the air entry path to said passage.

6. A vacuum cleaner comprising a casing forming a passage for air, said passage having an inlet and an outlet, a dust collecting means connected to said inlet and forming an air entry path thereto, means in said passage between said inlet and said outlet for removing foreign matter from the air passing therethrough, a motor disposed within said casing, and fan means driven by said motor and positioned in said passage for moving air therethrough, said fan means compiising two concentric impeller sections each having a plurality of vanes with one section being disposed within the other, and means arranged in cooperative relationship with said pluralities of vanes respectively to form a high-head low-flow fan and a low-head high-dow fan respectively, said latter means being formed so as to place said fans in series flow relation with each other and with said passage,- the outlet of'one of said fans being connected with the inlet of the other of said fans whereby said lowhead high-flow fan moves a substantial amount of air when the air entry path to said passage is substantially unobstructed and said high-head low-110W fan provides a substantial head when the air ow decreases because of an obstruction in the air entry path to said passage.

7. A vacuum cleaner comprising a casing forming a passage for air, said passage having an inlet and an outlet, a dust collecting means connected to said inlet and forming an air entry path thereto, means in said passage between said inlet and said outlet for removing foreign matter from the air passing therethrough, a motor disposed within said casing, and fan means driven by said motor and positioned in said passage for moving air therethrough, said fan means comprising two concentric impeller sections each having a plurality of vanes with one section being disposed within the other, and stationary shroud means arranged in cooperative relation with said concentric impeller sections forming a vortex fan with the inner concentric section and a radial fan with the outer concentric section respectively, said fans being arranged in series flow relation with each other and with said passage, the outlet of said vortex fan being connected with the inlet of said radial fan whereby said radial fan moves a substantial amount of air when the air entry path to said passage is substantially unobstructed and said vortex fan provides a substantial head when the air ow decreases because of an obstruction in the air entry path to said passage.

8. A vacuum cleaner comprising a casing forming a passage for air, said passage having an inlet and an outlet, a dust collecting means connected to said inlet and forming an air entry path thereto, means in said passage between said inlet and said outlet for removing foreign matter from the air passing therethrough, a motor disposed within said casing, and fan means driven by said motor and positioned in said passage for moving air therethrough, said -fan means comprising two concentric impeller sections each having a plurality of vanes with one section disposed within the other, a stationary shroud means arranged in cooperative relationship with said concentric impeller sections so as to form a radial Y References Cited in the le of this patent UNITED STATES PATENTS 877,485 Brooks Jan. 28, 1908 2,044,830 Carlstedt Iune 23, 1936 2,208,057 Skitch July 16, 1940 2,350,839 Szydlowski June 6, 1944 2,360,211 Doughman Oct. 10, 1944 2,624,064 Snyder Ian. 6, 1953 2,632,914 White Mar. 31, 1953 2,788,171 Kulow Apr. 9, 1957 FOREIGN PATENTS 512,452 Germany July 15, 1925 569,870 France Apr. 18, 1924 711,791 Germany Oct. 7, 1941 755,429 Great Britain Aug. 22, 1955 792,725 France Jan. 9, 1936 1,057,408 France Mar. 8, 1954 1,116,535 France May 8, 1956 

